fun <F : Any?> test(j: J<F>) {
  j.getFoo() /*~> Unit */
  j.setFoo(x = 1)
  val <receiver>: J<F> = j
  val <unary>: Int = <receiver>.getFoo()
  <receiver>.setFoo(x = <unary>.inc())
  <unary> /*~> Unit */
  j.setFoo(x = j.getFoo().plus(other = 1))
}
